Submolecular resolution in scanning probe images of Sn-phthalocyanines on Cu(1 0 0) using metal tips

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Kristof Buchmann
  • Nadine Hauptmann
  • Adam Foster

  • Richard Berndt

Research units

  • Kiel University
  • Radboud University Nijmegen
  • Kanazawa University

Abstract

Single Sn-phthalocyanine (SnPc) molecules adsorb on Cu(1 0 0) with the Sn ion above (Sn-up) or below (Sn-down) the molecular plane. Here we use a combination of atomic force microscopy (AFM), scanning tunnelling microscopy (STM) and first principles calculations to understand the adsorption configuration and origin of observed contrast of molecules in the Sn-down state. AFM with metallic tips images the pyrrole nitrogen atoms in these molecules as attractive features while STM reveals a chirality of the electronic structure of the molecules close to the Fermi level EF, which is not observed in AFM. Using density functional theory calculations, the origin of the submolecular contrast is analysed and, while the electrostatic forces turn out to be negligible, the van der Waals interaction between the phenyl rings of SnPc and the substrate deform the molecule, push the pyrrole nitrogen atoms away from the substrate and thus induce the observed submolecular contrast. Simulated STM images reproduce the chirality of the electronic structure near EF.

Details

Original languageEnglish
Article number394004
Pages (from-to)1-5
JournalJournal of Physics Condensed Matter
Volume29
Issue number39
Publication statusPublished - 22 Aug 2017
MoE publication typeA1 Journal article-refereed

    Research areas

  • atomic force microscopy, density functional theory, scanning tunneling microscopy, Sn-phthalocyanine

ID: 15675805